Apparatus for electric railway-vehicles.



J. LE C. DAVIS, DECD.

H. S. DAVIS, ADHHNISTRATRIX. APPARATUS FOR ELECTRIC RAILWAY VEHICLES.

APPLJCATION FILED JULY 29. 1913- Patented. eRuly 3, 1917.

WITNESSES:

UNITED STATES PATENT oEEIoE.

JOSEPH LE CONTE DAVIS, DECEASED, LATE OF PITTSBURGH, PENNSYLVANIA, BY MYRA SHIELDS DAVIS, ADMINISTRATRIX, OF PITTSBURGH, PENNSYLVANIA, ASSIG-NOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed July 29, 1913. Serial No. 781,747.

To all whom it may concern:

Be it known that JOSEPH LE CoNTE DAVIS, deceased, late of Pittsburgh, in the county of Allegheny and State of Pennsylvania, during his lifetime invented certain new and useful Improvements in Apparatus for Electric Railway-Vehicles, and that I, MYRA SHIELDS DAVIS, administratrix of the estate of the said JOSEPH LE CoNTE DAVIS, deceased, do hereby declare to the best of my knowledge and belief that the following specification, taken in connection with the drawings furnished and forming a part of the same, is a clear, true, and complete description of said improvement.

My invention relates to apparatus for electric railway vehicles, and it has special reference to dynamotors which are adapted for operation on both high and low-voltage electric railway systems.

The object of my invention is to provide a simple and effective means for adjusting the circuit connections of a dynamotor which is adapted, when connected to a high-voltage system, to supply energy for the vehicle" lighting and control circuits at a relatively low voltage and also to drive an air compressor, whereby the rotational speed of the dynamotor shall be maintained substantially constant, irrespective of the voltage of the system to which it is connected.

Since the advent of high-voltage direct current interurban railway systems, for instance such as are supplied with energy at 1200 or 1500 volts, there have been many instances where electric railway equipments or vehicles must be adapted for operation on both high and low-voltage sections which are interconnected. A common manner of operation of such mixed systems is to employ a dynamotor when operating on the high-voltage section for providing a voltage that is suitable for car lighting and control circuits, and which may also be employed for driving the air compressors. In such cases, when the car is traveling upon a lowvoltage city section of the system, the dynamotor is disconnected from the source of energy and the lighting and control circuits are directly connected to such source, while the compressor is driven by a separate lowvoltage motor, or, the lighting and control circuits are connected to the source of energy while the dynamotor is operated from the source and, consequently, at a much reduced speed. The chief difficulty encountered in such operation resides in the reduced speed of the dynamotor and compressor, which is, under certain circumstances, insufficient to provide the necessary air 1n the pneumatic brake system for the relatively large number of stops required in city service.

According to my invention, I propose to run the dynamotor continuously and at a constant speed whether it is operated from a low-voltage or a high-voltage section of a system, and I accomplish the result by eliminating one of the armature windings of the dynamotor when it is operated upon a lowvoltage section, and, at the same time, adjust the connections to supply the lighting and control circuits directly from the source of energy.

The single figure of the accompanying drawing illustrates an arrangement of appa ratus and circuit connections of a system embodying my invention.

Referring to the drawing, conductors 1 and 2 constitute portions of a plurality of adjacent trolley sections, section 1 being of the usual voltage (600 volts) that is employed for city electric railway operation and section 2 being of relatively high voltage such, for instance, as 1200 volts. Sections 1 and 2 are suitably insulated from one another and are supplied with direct current energy from any suitable source (not shown). A track rail 3 conveniently serves as the return circuit of the system, although any other suitable return circuit may be used.

As shown in the drawing, a dynamotor 4 having an armature 5, a plurality of commutators 6 and 7, a plurality of series field windings 8 and 9 and a shunt field winding 10, is connected in circuit with the high voltage trolley section 2 through an aux iliary switching device 11 and the return circuit or track 3.

An air compressor 13 of any well known type is adapted to be automatically associated with the shaft 14 of the dynamotor armature 5 by means of a clutch 15, as hereinafter set forth. The air compressor 13 is adapted to deliver air, under pressure, to

a main reservoir or tank 17 from which it is distributed through pipes 18 and 19 for use in the ordinary manner.

The clutch 15, may, of course, be operated in any well known manner, but preferably is operated automatically in accordance with the pressure of the air within the pneumatic system, through the agencyof a governor 20, a valve 21 actuated thereby, and an operating cylinder 22.

Those familiar with the art will readily understand the operation and functions of the apparatus just recited without more detailed description, it being understood that the air compressor 13 is automatically connected to the dynamotor 4 through the agency of the clutch 15 whenever the pressure of the air in the system is reduced to a predetermined amount for which the governor 20 is adjusted. The dynamotor 4 is provided with a plurality of armature windings 6 and 7 respectively connected to the commutators 6 and 7, and, under normal operation, said armature windings 6 and 7, together with thefield windings 8 and 9 are connected in series circuit relation between the high volt- -.age conductor 2 and the return circuit 3.

, 7" electrically associated with the commu- The armature winding 6 connected to commutator 6, together with its associated series field winding 8, and the armature'winding tator 7 "and its series field winding 9, are adapted to substantially divide the total voltage of the supply circuit, whereby conductor 23, which is connected to a point intermediate the several field windings 8 and 9, has impressed upon it substantially half of the total voltage of the system or 600 volts. The shunt field winding 10 is connected directly across the commutator 7 for the purpose of holdingthe speed constant and preventing the dynamotor from running away under light or no load conditions.

The switching device 11 comprises an upper movable contact member 25 and cooperating sets of stationary contact ter minals 26 and 27 and a lower movable con tact member 28 and ceperating sets of stationary contact terminals29 and 30. The contact members 25 and 28 are associated with a supporting rod 31, the lower end of which is provided with a piston 32 that is movably fitted into an air cylinder 33 of common and well known construction. A spring 34 is disposed between the piston 32 and an upper portion 35 of the cylinder 33 and tends, therefore, to maintain the movable contact members of the switching device 11 in their lower positions under normal high-voltage operating conditions. The air cylinder 33 constitutes an integral part of a casing 37 having a pressure chamber 38 and an inlet chamber 39. Openings or ports 40 and 41 are provided in the upper walls of the respective chambers 38 and 39 and are opened and closed by valves 42 and 43 which are mounted upon a stem 44. A spring 45 normally causes the valve 43 to close the port 41 between the inlet chamber 39 and the pressure chamber 38, and, at the same time, holds the valve 42 in such position that the exhaust port 40 between the chamber 38 and the atmosphere is open.

For governing the operation of the valve just described, a movable magnetizable core high-voltage operation, is of substantially half voltage, is connected through the contact members 25 and 26 of the switching device 11 and conductor 50 to a lighting system 51 and a control system 52 marked Control System, which are illustrated diagrammatically in the drawing. Thus, if the dynamotor be connected to a 1200 volt circuit, substantially half that voltage, or 600 volts, is delivered to the car lighting system and control circuits.

When the car or vehicle enters the lowvoltage section 1 of the trolley conductor, the operator may adjust the connections of the dynamotor 4 for the desired operation by closing a manually-operated switch 53 which completes a circuit from trolley 'section 1 through collector 49, conductor 54, switch 53, resistor 55, conductor 56, energizing winding 48 of the electromagnet 47 and conductor 57 to the returncircuit 3. Upon completion of the circuit just described, the movable core 47 and the valve stem 44 are moved downwardly to open the inlet port 41 and close the exhaust port 40. Thereupon, an operating fluid under pressure is admitted to the pressure chamber 38 to force the piston 32 and its associated rod 31 and contact members 25 and 28 to their upper positions; In so doing, the upper contact member 25 disconnects the lighting system 51 and control circuits 52 from the conductor 23 and connects them directly to the trolley section 1 through cooperating contact members 25 and 27, conductor 58 and collector 49.

Inasmuch as the vehicle is now operating upon a low-voltage, or 600 volt, trolley circuit, the lighting system 51 and control circuits 52 are maintained at the same voltage that was impressed thereon during the 1200 volt operation.

Concurrently with this action, switch member 28 interrupts the main circuit between the series field winding 9 and the armature winding 7 which is connected to the commutator 7 and completes a circuit from the series field winding 9 through .con-

ductor 59, contact members 28 and 29 and conductor 60 to the return circuit 3. Thus, the armature winding 6 connected to the commutator 6 and the series field windings 8 and 9 are connected directly across the low-voltage. system, while the connections of .the shunt field 10 are unchanged. Thus, the armature winding 6 connected to the commutator 6 and the field windings 8 and 9 act in conjunction, in accordance with well known principles, to drive the air compres sor 13 at the same speed which was maintained under high-voltage operation, while the shunt winding 10 still serves, in conjunction with the armature winding 7 associated with the commutator 7, to limit the speed of the machine when under light load.

It will be noted, therefore, that the same voltage is applied to the lighting system and control circuits, and the same speed of the air compressor and dynamotor is maintained, irrespective of Whether the equipment is operated upon a high-voltage or a lowvoltage section of the system.

Various modifications in the circuit connections and arrangement and location of apparatus may be made without departing from the'spirit and scope of my invention.

I claim as my invention:

1. The combination with a source of energy, and a dynamotor having a plurality of armature windings and field windings connected thereto, of means for eliminating certain of said windings from the circuit of said source of energy under predetermined conditions.

2. The combination with a supply circuit, a return circuit and a dynamotor having a plurality of armature and field windings in series circuit relation between said circuits, of means for removin a portion of said armature and field win ings from said series circuit.

3. The combination with a supply circuit, a return circuit and a dynamotor having a plurality of armature and field windings connected in series circuit relation between said circuits, of a switching device for rearranging the circuit connections of said armature and field winding whereby a substantially constant speed is maintained under difierent voltage conditions of opera tion.

4, The'combination with a supply circuit, a return circuit and a dynamotor having a plurality of armature and field windings connected between said circuits, of a mechanical load adapted to be driven by said dynamotor and a switching device for adjusting the circuit connections of said armature and field windings, whereby said mechanical load is driven at a substantially constant speed under widely difl'erent voltage conditions of the supply circuit.

5. In a system of distribution adapted for high and low-voltage operation, the combination with a supply circuit, a return circuit and a dynamotor having a plurality of armature windings and series field windings normally connected in series circuit relation for high-voltage operation, of a switching device for eliminating one of the armature windings from said series circuit under lowvoltage operating conditions.

' 6. In a system of distribution adapted for high and low-voltage operation, the combination with a dynamotor'electric machine comprising a plurality of armature windings and series field windings connected in series circuit relation under high-voltage operating conditions, a shunt field winding and a lighting system normally connected to a point intermediate said series windings, of means for concurrently eliminating one of said armature windings from, and transferring said lighting system to, the supply circuit for operation under low-voltage conditions.

7. The combination with a supply circuit and a return circuit, of a dynamotor having a plurality of armature and field windings in series relation between said circuits, translating devices connected to a point between said field windings, and means for connecting said translating devices to said supply circuit and removing one of said armature windings from said series circuit under predetermined conditions.

8. In a system of distribution for electric railway systems comprising a high-voltage and a low-voltage section, the combination with a dynamotor, an air compressor adapted to be driven thereby, and translating devices connected to a point intermediate the windings of said dynamotor under highvoltage operating conditions, of a switching device for adjusting the circuit connections of said dynamotor and said translating devices under low-voltage operating conditions, whereby the voltage of the translating devices and the speed of the dynamotor are maintained substantially constant under both operating conditions.

9. In a control system, the combination with a plurality of sources of energy, and a dynamotor adapted to be connected to said sources and having a plurality of armature windings and field windings, of means for changing the circuit connections of the dyna- 'motor windings to adapt the same for connection to the respective sources. 10. In a control system, the combination with a source of energy. and a dynamotor connected thereto and having a plurality of armature windings and field windings, of switching means for utilizing all or a portion of said windings. I

11. In a system of distribution adapted for high and for low voltage operation, the combination with a supply circuit and a dynamotor having a lurality. of armature and field windings, means for arranging I the circuit connections of said windings to combination with a supply circuit and a dynamotor having a plurality of armature and field windings, of a mechanical load adapted to be driven by said dynamotor,

an electrical. load adapted to be supplied thereby, and means for changing the circuit connections of said dynamotor windings-to maintain substantially constant speed of operation of said mechanical load and constant voltage upon said electrical load under both high and low voltage operating conditions. 7 I

13. The combination with a supply circuit adapted to deliver widely difierent voltages, a dynamotor connected thereto and having a plurality of armature and field windings, and a mechanical load adapted to be driven by said dynamotor, of means for changing the circuit connections of said windings to insure a substantially constant operating speed for said mechanical load irrespective of the voltage ofsaid source.

14. The combination with a supply circuit adapted to deliver high and low voltage and a dynamotor connected thereto under high voltage conditions, of electrical apparatus connected to a portion of said dynamotor and adapted to receive energy at a voltage less than that of the supply circuit, means for changing the connections of said dynamotor and said electrical ap-- paratus under low voltage conditions to malntain a constant speed of said dynamotor and a constant voltage supplied to said electrical apparatus.

field and armature windings.

16. In a control system, the combination with a source of direct-current energy and a dynamotor connected thereto and comprising a plurality of field windings, a plu- I rality of commutator cylinders and a plurality of armature windings severally connected to said commutator cylinders, of means for changing the circuit connections of said field and armature windings, said field windings and armature windings being initially connected in series-circuit relation, and selective means for eliminating one of the armature windings from said series circuit.

17. In a system of distribution adapted for high and low-voltage operation, the combination with a supply circuit, a return circuit and a dynamotor having a plurality of armature windings and series field windings normally connected in series-circuit relation for high-voltage operation, of means for eliminating one of the said windings from said series circuit lmder low-voltage operating conditions.

In testimony whereof, I have hereunto subscribed my name this 17th day of July,

MYRA SHIELDS DAVIS, Administratria: of Joseph Le Gonte Dam's,

deceased.

Witnesses: 1

HELENE BARoHrnLn, Cmnws HARRY BRAOKEN. 

